Aerial modification of stem,Stem tendrils,Thorns,Phylloclade,Cladodes,Leafless, Spirally Coiled Branches,Passiflora or Modification,Duranta and Prunus

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Aerial modification of stem

1. Stem tendrils. These are leafless, spirally coiled branches. They help the weak stems to climb up. It can be modification of an axillary bud. e.g. Passiflora or modification of terminal bud e.g. Grape vine.

Tendril Climber of Grape Vine

2. Thorns. These are hard, pointed, straight structures. These are modified axillary or terminal buds. They act as organs of defence. In Duranta and Prunus the thorn bear leaves. In carissa thorns are modified terminal buds.

3. Phylloclade. These are green flattened stems having nodes and internodes with leaves reduced to spines. In Opuntia and Euphorbia the phylloclade are succulent and conserve water. It is a characteristic of xerophytes.

Tendril Climber of Passiflora

Tendril Climber of Cucurbita

Stem Modifications 1. Stem Spine 2. Leaf 3. Stem 4. Stem Spine 5. Leaf 6. Adhesive Disc 7. Stem	Phylloclade A. Leaves B. Stem C. Flower
Cladode

4. Cladodes. It is a phylloclade with only one internode. They are axillary in position and bear buds, scales and flowers e.g. Asparagus.